Method and apparatus for calibrating a paper sensor to account for media holes

ABSTRACT

The image forming device includes an image forming section in which an image is formed on the prepunched paper; a paper feed path through which paper is fed to and from the image forming section during a process in which an image is formed on the paper; one or more sensors arranged along the paper feed path to monitor a flow of the prepunched paper as it is fed through the paper feed path; and a processor for receiving signals from the sensors and map data of the prepunched paper, and for analyzing the signals and the map data to determine if there is a paper jam along the paper feed path, wherein the map data indicates locations of all holes, cut-outs, and notches formed in the prepunched paper. A method of using the image forming device is also disclosed.

FIELD OF THE INVENTION

This disclosure relates to a system and method for tracking the movement of paper through a multi-functional peripheral (MFP) or a printer. The disclosure further relates to a nontransitory computer readable medium that is encoded with a program for tracking the movement of paper through a multi-functional peripheral (MFP) or a printer.

RELATED ART

Multi-functional peripheral devices, sometimes referred to as MFPs, have a variety of functions, such as copying, network printing, scanning, faxing, and Transmission Control Protocol/Internet Protocol (TCP/IP) communication. Feeding a sheet of paper or other recording medium through an MFP, or a conventional printer, presents several challenges. Because of the high speed at which the paper moves through such a device, the paper will occasionally jam within the paper feed path.

In order to ensure smooth functioning of the device, most devices have a series of sensors arranged along the paper feed path to monitor the flow of the paper along the feed path. Typically, the sensors are light sensors which determine the leading edge and the trailing edge of the paper as it moves along the paper feed path. The light sensor has a light emitter arranged on one side of the paper feed path, and a light receiver arranged on an opposite side of the paper feed path so that the paper transits between the light emitter and the light receiver. When the light receiver receives light emitted from the light emitter, it is assumed that there is no paper at that portion of the paper feed path. When the light receiver stops receiving light from the light emitter, it is assumed that there is a sheet of paper at that portion of the paper feed path. See FIG. 1.

Accordingly, when the light receiver stops receiving light from the light emitter, the system determines that the leading edge of the sheet of paper is at the sensor. When the light receiver resumes receiving light from the light emitter, the system determines that the trailing edge of the sheet of paper is at the sensor.

Sensing systems as described herein can be used to monitor the flow of paper through the paper feed path. They can also be used to calculate the size of a sheet of paper.

Some users of printing devices prefer to use sheets of paper or recording medium that are prepunched with holes along the margin thereof. A common example is paper having three spaced holes along the left margin arranged in the “three hole punch” format for putting the paper in a three ring binder. In other situations, paper has a window of a cut-out preformed in the sheet of paper to allow an address or title or other piece of information to be seen through the cut-out portion. Further, in other situations, paper is preformed with notches along an edge thereof.

A problem sometimes occurs when the above-described sensors are used with prepunched paper or paper preformed with cut-outs or notches. In those situations, it is possible that the sensor will mistake one or more of the preformed holes, cutouts, or notches as the trailing edge of the sheet of paper. In that case, the system may erroneously determine that a paper jam exists or may erroneously calculate the size of the sheet of paper. See FIG. 2.

SUMMARY

In order to address the foregoing issues, an image forming device for printing a prepunched paper has been developed. The image forming device comprises:

an image forming section in which an image is formed on the prepunched paper;

a paper feed path through which paper is fed to and from the image forming section during a process in which an image is formed on the paper;

one or more sensors arranged along the paper feed path to monitor a flow of the prepunched paper as it is fed through the paper feed path; and

a processor for receiving signals from the sensors and map data of the prepunched paper, and for analyzing the signals and the map data to determine if there is a paper jam along the paper feed path, wherein the map data indicates locations of all holes, cut-outs, and notches formed in the prepunched paper.

The image forming device further comprises a memory for storing the map of a prepunched paper.

The image forming device further comprises a scanner for scanning the prepunched paper prior to printing.

The image forming device further comprises a processor for receiving a scanned image of the prepunched paper and for mapping locations of all holes, cut-outs, or notches in the prepunched paper.

The image forming device according to claim 1, wherein the processor uses the map data to account for holes, cut-outs, and notches in the prepunched paper so as to avoid any false indications of a trailing edge of the prepunched paper.

The image forming device further comprises a plurality of paper feeding trays, and the map data can include an identification of one of the paper feeding trays that contains the mapped prepunched paper.

The sensors of the image forming device may each include a light emitter and a light receiver.

An image forming method for printing a prepunched paper comprises:

creating a map of locations of all holes, cut-outs, and notches formed in the prepunched paper;

feeding the prepunched paper along a paper feed path to and from an image forming section;

forming an image on the prepunched paper by the image forming section;

using one or more sensors to detect a leading edge and a trailing edge of the prepunched paper as it moves along the paper feed path to detect a paper jam; and

using the map to avoid any false indications of a trailing edge of the prepunched paper.

In the image forming method, the method is carried out in a multi-peripheral function device, which device comprises a memory for storing the map of the prepunched paper.

In the image forming method, the map is created by scanning the prepunched paper prior to printing with a scanner.

And, a nontransitory image reading medium is encoded with the foregoing methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a conventional system for detecting the leading and trailing edge of a sheet of paper.

FIG. 2 is a view of the system of FIG. 1 illustrating its use on prepunched paper.

FIG. 3 is a schematic view of an MFP with a scanner.

FIG. 4 is a view of a sheet of paper that is mapped in accordance with an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a basic process according to one embodiment of the present invention.

FIG. 6 is a flowchart illustrating a process for mapping a sheet of paper according to one embodiment of the present invention.

FIG. 7 is a flowchart illustrating a print process according to one embodiment of the present invention.

FIG. 8 is a schematic view of a display of the MFP according to one embodiment of the present invention.

FIG. 9 illustrates the operation of a sensor in the paper feed path according to an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A system has now been developed to avoid or minimize the aforementioned issues concerning the use of sensors with a paper 30 or recording medium having holes 40, notches, or cut-outs formed therein, hereinafter referred to as prepunched paper.

Mapping:

FIG. 5 is a flowchart that illustrates the basic mapping operation of an embodiment of the present invention. According to the embodiment of FIG. 5, prior to running a print job using prepunched paper on an MFP 20, an exemplary sheet of the prepunched paper 30 is scanned by the scanner 10 of the MFP 20 (step S110). The scanned prepunched paper is then mapped by the MFP 20 to identify the location of all such holes 40, notches, and cut-outs formed in the prepunched paper (step S120). Further details of the mapping process are shown in FIG. 6. The map of the prepunched paper is then saved in a memory 50 in the MFP 20 (step S130). A label, such as “3 hole punch paper” is then assigned to the map (step S130) and saved with the map. If desired, the user can also assign a paper tray to the stored map and save the paper tray information together with the map name and data (step S140).

Mapping of the paper is illustrated in FIGS. 4 and 6. According to one embodiment, after the paper 30 is scanned in step S110, a first hole 40 is identified in the sheet of prepunched paper (step S210). Then, a smallest possible rectangular boundary 60 that can include all portions of the particular hole 40 is created (step S220). See FIG. 4.

Coordinates are then assigned to the rectangular boundary, e.g., (x1-x2; y1-y2) and saved (S230). The system then determines if there is another hole that has not yet been mapped (S240). If so, the process of identifying the hole, creating a boundary, assigning coordinates to such boundary, and saving the data is repeated for each hole or opening in the paper (YES at block S240). If all holes have been mapped (NO at block S240), the data is then saved to a memory. As indicated above with respect to the flowchart in FIG. 5, each map may then be labeled (S130) and, if desired, assigned to a specific paper tray (S140).

The map data can also include the overall dimensions of the paper, such as 8½ by 11 inches, or A4 size.

As an alternative, to creating the map on the MFP 20, the map can be created by an external device and sent to the MFP 20. Furthermore, for commonly used prepunched papers, such as that which is punched for a three ring binder, one or more maps can be made in advance and stored. For such common prepunched papers, the maps could be made in any manner and programmed into a memory. In such a case, it would not be necessary to scan the prepunched paper to determine the location of such holes.

Each of the individual steps or processes identified above, e.g., identifying the holes, creating boundaries for each hole, and assigning coordinates to the boundaries, can be done by any number of ways that would be readily known to one of ordinary skill in the art. Accordingly, detailed descriptions thereof are omitted.

Printing:

Once the mapping process has been completed, the user can then run a print job using the mapped prepunched paper as illustrated in FIG. 7.

The first step for running the print job according is to load the image to be printed (S 310). The image can be loaded in any number of conventional ways. For example, image data that is prestored in a memory 70 in the MFP 20 can be selected, for example using a display 80 on the MFP 20. See FIG. 8. In an image selection box 82, using selector 84, the user can select from a drop down menu, which device is holding the image data to be printed. The selection of devices could include a number of external devices, the MFP scanner 10, or a memory 70 in the MFP 20. If the scanner 10 is selected, the image data can be created by scanning an original document using the scanner 10 of the MFP 20. Once the device is selected, the user can select, using drop down menu 86, the name of the file for the image data. One of ordinary skill in the art could create and use alternative methods of selecting and/or loading the device and/or image data.

Once the image data is identified and selected, the user then selects copy conditions from menus found in the copy conditions section 88 of the display 80 (step S320). Such copy conditions can include any number of known options, including but not limited to the number of pages, two-sided copying, magnification/reduction, etc. Because such features are all well known, details of the copy conditions section 88 are omitted.

Once the image data has been selected, and the copy conditions have been set, the user can then load a map from the map loading section 90 of the display 80. For example, the map loading section 90 may include a drop down menu 92 from which the user can select a preloaded map of prepunched paper. The maps could include maps created according to the methods set forth above. According to one embodiment, the drop down menu 92 could include one option for whole paper, i.e., paper that is not prepunched.

As explained above, the mapped data could be stored and identified by reference to a particular paper tray in the MFP 20. In that case, the user would simply identify the desired paper tray from the drop down menu 92.

After the image data has been selected (step S310), the copy conditions have been set (S320), and the map data has been loaded (S330), the user may initiate the process using the start button 94 on the MFP display 80. Once the start button 94 is pressed, the printer driver will send the print job, together with the map of the paper being used.

FIG. 9 illustrates an embodiment of the present invention showing how the sensors use the paper map to avoid an inadvertent indication of a paper jam. In particular, FIG. 9 shows how the sensors determine whether or not there is a paper jam. The flowchart of FIG. 9 relates to only one sensor 74 in the MFP 20. However, the process is repeated for each sensor along the paper feed path 76 in the MFP 20.

As the paper 30 begins moving through the paper feed path 76, the light receiving portion of the sensor 74 is receiving light. As the leading edge of the paper 30 reaches the sensor 74, the light receiving portion stops receiving light, thus forming the OFF EDGE of the sensor output (Step S410). If YES at S410, the sensor 74 detects the leading edge of the paper, and stores time T₁ (Step S420). When the trailing edge of the paper 30 passes the sensor 74, the light receiving portion of the sensor again receives light (YES at S430), thus forming the ON EDGE of the sensor output, and time T₂ is stored (Step 440). The system then calculates the difference between T₂ and T₁, i.e., T₂−T₁=T₃ (Step S450). If T₃ matches with the expected time for the known paper size (YES at S460) then, it is determined that there is no paper jam, and the sensor 74 awaits the next shhet of paper. If T₃ does not match with the expected time for the known paper size (NO at S460) then, a check is made to see if T3 matches with any openings in the paper that have been identified with the paper map (S480). If NO at S480, then it is determined that a paper jam exists. If YES at S480, the time T₂ is reset, and the sensor continues to wait for the next time the trailing edge passes the sensor (S490).

In this way, the aforementioned sensors can anticipate and account for holes, cut-outs, and/or notches in the paper being fed so as to minimize the likelihood of an erroneous indication of a paper jam during the printing process.

A CPU 72 in the MFP 20 can control the aforedescribed processes.

While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein. The present invention includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g. of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to”.

In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present In that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language “present invention” or “invention” should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. 

What is claimed is:
 1. An image forming device for printing a prepunched paper, the image forming device comprising: an image forming section in which an image is formed on the prepunched paper; a paper feed path through which paper is fed to and from the image forming section during a process in which an image is formed on the paper; one or more sensors arranged along the paper feed path to monitor a flow of the prepunched paper as it is fed through the paper feed path; and a processor for receiving signals from the sensors and map data of the prepunched paper, and for analyzing the signals and the map data to determine if there is a paper jam along the paper feed path, wherein the map data indicates locations of all holes, cut-outs, and notches formed in the prepunched paper.
 2. The image forming device according to claim 1, further comprising a memory for storing the map of a prepunched paper.
 3. The image forming device according to claim 1, further comprising a scanner for scanning the prepunched paper prior to printing.
 4. The image forming device according to claim 3, further comprising a processor for receiving the scanned image of the prepunched paper and for mapping locations of all holes, cut-outs, or notches in the prepunched paper.
 5. The image forming device according to claim 1, wherein the processor uses the map data to account for holes, cut-outs, and notches in the prepunched paper so as to avoid any false indications of a trailing edge of the prepunched paper.
 6. The image forming device according to claim 1, further comprising a plurality of paper feeding trays, and the map data can include an identification of one of the paper feeding trays that contains the mapped prepunched paper.
 7. The image forming device according to claim 1, wherein the sensors each include a light emitter and a light receiver.
 8. An image forming method for printing a prepunched paper, the method comprising: creating a map of locations of all holes, cut-outs, and notches formed in the prepunched paper; feeding the prepunched paper along a paper feed path to and from an image forming section; forming an image on the prepunched paper by the image forming section; using one or more sensors to detect a leading edge and a trailing edge of the prepunched paper as it moves along the paper feed path to detect a paper jam; and using the map to avoid any false indications of a trailing edge of the prepunched paper.
 9. The image forming method according to claim 8, wherein the method is carried out in a multi-peripheral function device, which device comprises a memory for storing the map of the prepunched paper.
 10. The image forming method according to claim 8, wherein the map is created by scanning the prepunched paper prior to printing with a scanner.
 11. A nontransitory computer readable medium encoded with a program for causing an image forming apparatus to perform an image forming method for printing a prepunched paper, the method comprising: creating a map of locations of all holes, cut-outs, and notches formed in the prepunched paper; feeding the prepunched paper along a paper feed path to and from an image forming section; forming an image on the prepunched paper by the image forming section; using one or more sensors to detect a leading edge and a trailing edge of the prepunched paper as it moves along the paper feed path to detect a paper jam; and using the map to avoid any false indications of a trailing edge of the prepunched paper.
 12. The nontransitory computer readable medium according to claim 11, wherein the method is carried out in a multi-peripheral function device, which device comprises a memory for storing the map of the prepunched paper.
 13. The nontransitory computer readable medium according to claim 11, wherein the map is created by scanning the prepunched paper prior to printing with a scanner. 